Whether or not you are dieting, skipping meals drains whatever energy reserves you store, and is likely to make you feel more tired than light or weightless.
That’s because skipping a meal makes the blood sugar level drop dramatically. Instead of sustaining the body by the gradual breakdown of sugar into energy that regular food intake provides, the practice can only make energy levels crash or plummet, causing even more lethargy. It can also make the blood sugar level spike, as the body signals stored energy in the form of fat or glucagon to break down into simple sugar.
Fluctuations in blood sugar level, as a result of skipping meals frequently, can lead to the development of diabetes later on in life. Aside from depleting energy stores, skipping a meal also withholds from the body the nutrients that enable cells, tissues, and organs to function properly.
Finally, skipping a meal can interfere with one’s metabolism. Instead of allowing the body to break down food into simple sugar each time one eats, skipping a meal leaves the body with nothing to do. As such, the body’s capacity to break down food slows down. The next time you consume a big meal, your body’s metabolism may not be as fast anymore, hence you end up converting the food into fat, which is the body’s means of energy storage.
In the end, what is believed to make the body shed more fat can actually make it do the opposite.